Integrated circuits (ICs) such as amplifiers or voltage regulators generate heat as they operate. Excessive heat over an extended period of time can cause damage to an IC. Accordingly, IC packages are typically manufactured to include a structure for dissipating the heat generated by the IC. These components could include, for example, a conductive pad heat sink that has a large surface area. The case of a conductive pad, the conductive pad may be made of metal, such that it is thermally conductive. The IC package may be manufactured such that the conductive pad is in physical contact with the IC on the interior of the IC package, and heat generated from the IC is transferred to the conductive pad. Part of the conductive pad may be located external to the IC package, thus allowing heat to be transferred exterior of the IC package. The conductive pad may also provide a stable ground connection to the IC from a printed circuit board (PCB) on which the IC package is mounted by connecting with one or more layers of the PCB.
FIG. 1 illustrates a prior art example of an IC 10 manufactured within an IC package 12. In the example of FIG. 1, the IC 10 includes an operational amplifier (op amp) circuit 14. The IC 10 has eight terminals. Terminals 1 and 5 of the IC 10, each labeled “NC,” are not internally connected. Terminal 2 of the IC 10, labeled “IN−,” is a non-inverting input to the op amp circuit 14. Terminal 3 of the IC 10, labeled “IN+,” is an inverting input to the op amp circuit 14. Terminal 4 of the IC 10, labeled “Vs+,” is a negative terminal of the supply voltage to the op amp circuit 14. Terminal 8 of the IC 10, labeled “EN,” is an enable input to the op amp circuit 14. Terminal 7 of the IC 10, labeled “Vs−,” is a positive terminal of the supply voltage to the op amp circuit 14. Terminal 6 of the IC 10, labeled “OUT,” is the output terminal of the op amp circuit 14.
As described above, the IC 10 may generate heat as it operates in conjunction with circuitry to which the IC 10 may be connected on an associated PCB. To alleviate excessive heat, the IC package 12 may be manufactured with a conductive pad 16 in contact with and beneath the circuit die 14. The conductive pad 16 may be formed from a type of metal, alloy, or other electrically and thermally conductive material, such that heat generated by the IC 10 may be conducted and transferred through the conductive material to a portion of the conductive pad 16 that is exposed at the underside of the IC package 12. In addition, the exposed conductive pad 16 at the underside of the IC package 12 may be connected to the PCB on which the IC package 12 is mounted, such as by soldering. The connection may further help dissipate heat generated by the IC 10, as well as provide a stable electrical ground connection to the PCB for the IC 10.
A connection may be made between two terminals of an IC. In the example of an opamp circuit, it would be common to feedback connect output terminal 6 of FIG. 1 of the circuit 14 to one of the inputs of the op amp circuit 14, such as terminal 2. Thus, the output terminal OUT of the IC 10 may often be electrically connected to the inverting input terminal IN− of the IC 10.